This invention relates to electrochemical cells in general and more particularly to an improved air electrode for electrochemical cells, particularly fuel cells with an alkaline electrolyte containing silver coated carbon as the catalytic material.
The use of carbon coated with noble metals, such as silver, as the cathode material i.e., for oxygen reduction, in fuel cells is known. Although such electrode material has been found usable in fuel cells operated with hydrogen and oxygen, it is less suited for air operation, i.e, if air is used instead of oxygen. For, replacing oxygen by air causes, as it does with other cathode materials, a decrease of the electrode potential by about 100 mV.